Affordable and Conservative Full Mouth Reconstruction of Generalized Wear

Worn or eroded dentition is a common issue faced by many individuals that results in clinical situations like the case detailed in this article. Factors such as age, diet, bruxism, and acid erosion can contribute to the gradual loss of tooth structure.³ When left untreated, this deterioration can lead to various complications, including sensitivity, functional deficiencies, and compromised esthetics. Restoration of the entire occlusal table of a worn or eroded tooth is often accomplished with an indirect restoration. In a single tooth scenario, such a procedure is simple, affordable, and tolerable for most patients. However, in cases involving generalized erosive tooth wear, recommending that same indirect restorative approach quickly compounds the complexity and cost of treatment-often to the point of unfeasibility.

In these situations when optimal, full-mouth treatment is not an option, the cost-modified solution usually involves restoring the dentition in sections or even one tooth at a time. Unfortunately, sectional treatment of generalized wear limits the larger solution of the fundamental problems and ultimately results in a mouthful of crowns made to fit within the worn dentition rather than to restore it. Relatedly, sectional treatment often requires significant tooth preparation to achieve adequate restorative material space.

Even when treatment is staged, the cost associated with full-mouth rehabilitation can be prohibitive for many patients, especially those with limited dental insurance coverage.⁴ Moreover, the average patient's ability to afford treatments and/or the pace at which these treatments are reimbursed by insurance providers may not align with the progressive nature of tooth wear or the typically expedited treatment timelines. This leaves both providers and patients to decide between optimal treatment, which traditionally must be both accomplished and paid for all at once, and practical treatment, which often results in either incomplete or piecemeal solutions.

In recent years, 3D printing technology has revolutionized dentistry in many ways. One of the most exciting developments is the advent of the 3D printed crown. With every new formulation, crown resins are becoming increasingly esthetic, strong, and durable, and as a result, they are quickly becoming an appealing option for many restorative applications. Forgoing the use of traditional crown materials, such as ceramics or metal alloys, and utilizing 3D printed crown resins in additive restorative applications offers several distinct advantages, including the following:

• Conservative preparation. One of the primary benefits of using 3D printed crown resins is the ability to produce extremely thin restorations (eg, 300 µm or less), which permits placement with less preparation and preserves tooth structure.⁵ Unlike traditional crowns, which require significant tooth preparation to accommodate typical minimal material thicknesses, 3D printed crowns can be designed to bond and restore a worn tooth only in the areas requiring additive treatment, minimizing the need for excessive tooth reduction.

• Favorable esthetics. 3D printing technology facilitates precise customization of restoration design, ensuring a perfect fit and natural appearance.⁶ The ability to match the color, shape, and texture of the natural teeth allows these conservative 3D printed restorations to blend with both the natural and restored dentition, enhancing patient satisfaction and confidence.

• Enhanced durability. Even in the most conservative applications, 3D printed crown resins offer exceptional strength and durability.⁷ Because these materials are engineered to withstand the forces of mastication and resist wear and staining over time, they provide long-lasting results that are comparable to traditional approaches to rebuilding occlusion (eg, traditional provisional crowns, direct composite bonding, etc).

• Cost-effectiveness. From a financial standpoint, 3D printed crown resins offer substantial savings when compared with traditional indirect restorative materials.⁸ The rapid production process, minimal material waste, and reduced need for outsourced laboratory fabrication result in drastically lower overhead costs, which translates into more affordable treatment options for patients.

When addressing generalized wear cases, building up the posterior dentition is usually necessary to gain the restorative space required to achieve ideal tooth proportions and function for the anterior teeth if not to restore proper occlusion and prevent further breakdown.⁹ Traditionally, this meant obligating a patient to a full mouth of laborious and costly procedures, problematic provisional restorations, and then as soon as possible, placement of a final restoration on every tooth.

But with modern digital materials and methods, by placing 3D printed additive occlusal veneers on the posterior segments, occlusion can be stabilized, function restored, and further deterioration prevented for a fraction of the time, money, and effort. After the posterior occlusion is restored, the anterior segments can be finalized with conventional ceramic materials to achieve optimal esthetics and durability. With this approach, the restoration of the remaining posterior teeth with ceramic final crowns can be completed periodically, in small sections, or even on a tooth-by-tooth basis when necessary due to resin breakdown. This way, the more expensive treatment of the individual posterior teeth with ceramics can be accomplished over time without initially ignoring the occlusal problems or aggressively reducing the tooth structure.

This staged treatment approach not only limits the cost and complexity typical of a full-mouth rehabilitation but also better accommodates individual patient budgets and common dental insurance reimbursement models. Rather than attempting to address all of the dental issues in a single treatment cycle, patients can spread their treatment out over multiple years, making it more feasible within the constraints of their personal finances and insurance benefits. The following case report demonstrates this staged treatment approach to restoring generalized wear.

A female patient presented with typical signs of generalized erosive tooth wear (Figure 1 through Figure 4). When occlusal breakdown is identified in the early or intermediate stages, it is often in younger patients, like the one in this case, who are less likely to have the necessary financial resources available to pursue traditional full-mouth reconstructive treatment. This is often the reason why patients wind up pursuing compromised, single-tooth solutions that are covered by their annual dental insurance, which results in restorative results like this patient's recently completed ceramic crown on tooth No. 19 (Figure 5).

Prior to restoration, the etiology of the patient's erosive tooth wear (ie, gastroesophageal reflux disease) was identified and controlled. A treatment plan that included placement of 3D printed occlusal veneers on all of her posterior teeth, followed by full-coverage ceramic crowns for her maxillary anterior teeth and labial ceramic veneers for her mandibular anterior teeth, was presented and accepted. Next, the initial restoration design was completed (3Shape) (Figure 6 and Figure 7). Although the design of the final anterior restorations would be completed after tooth preparation, the design of the additive posterior restorations was finalized for 3D printing (Rayware, SprintRay) (Figure 8), and the posterior restorations were produced ahead of time (Ceramic Crown, SprintRay) and verified on a model (Study Model White 2, SprintRay) (Figure 9 and Figure 10).

When the patient presented for reconstructive treatment, the posterior occlusal veneers were prepared for bonding with microabrasion using 50 µm aluminum oxide and then a bonding agent was applied (OptiBond^™ Solo Plus, Kerr Dental). The surfaces of the natural tooth and existing ceramic crown were etched with a 38% phosphoric acid gel (Etch-Rite^™, Pulpdent) and a 9.6% hydrofluoric acid gel (Porcelain Etch Gel, Pulpdent), respectively, before receiving an application of the bonding agent, and then the occlusal veneers were bonded using a dual-cure resin cement (RelyX^™ Unicem 2, 3M) (Figure 11 and 12). This reestablished proper posterior occlusal morphology, clinical crown height, and occlusal vertical dimension, which would allow for ideal restoration of the anterior teeth (Figure 13), all with little or no local anesthesia required. With the posterior dentition now optimized, the anterior tooth crown/veneer preparations could be accomplished with a more manageable, smaller-scale procedure involving less tooth reduction, less anesthetic, and less total procedure time (Figure 14). After the anterior preparations were complete, provisional crowns (Integrity^®, Dentsply Sirona) were placed (Figure 15).

Once the final ceramic crowns were designed and fabricated (IPS e.max^®, Ivoclar), the patient was recalled, and they were placed (Figure 16 through Figure 18). The 3D printed occlusal veneers would remain on the posterior teeth. Although the esthetic and functional results were good and stable across the entire dentition (Figure 19), the posterior teeth were arguably still "in treatment." However, with the fundamental problems relating to bite collapse, occlusal instability, pulpal sensitivity, and progressive loss of tooth structure now addressed, future restoration of the posterior teeth with ceramic crowns could now be accomplished one tooth at a time in a manner that suits the patient's finances without compromising the overall results.

In the following year after the initial treatment, the 3D printed occlusal veneer on tooth No. 14 fractured (Figure 20). There was no pain or biologic pathosis noted, and the patient was only experiencing as much mild tooth sensitivity as was present prior to treatment, so the optimal solution was a simple, single posterior ceramic crown (IPS e.max^®, Ivoclar) (Figure 21). Although this ceramic crown (as well as all of the other future posterior ceramic crowns) would have been an additional and significant out-of-pocket expense for this patient if included in the original restorative intervention, now in the following calendar year, new insurance benefits were applicable, and she was better able to afford it. As the years pass, and more of this patient's posterior 3D printed restorations are converted to final ceramic crowns, this approach could ultimately save her not only tens of thousands of dollars in out-of-pocket costs but also additional tooth structure, chair time, scheduling efforts, and anxiety when compared with traditional dental reconstruction.

The utilization of 3D printed dental crown resins represents a paradigm shift in the treatment of worn or eroded dentition. Given that many patients with generalized tooth wear also have limited financial resources, by offering a conservative, cost-effective, and conscientious solution like the one in this case, these patients have a better chance at achieving comprehensive treatment without the typical compromises. The use of ever-advancing 3D printed crown resins can help address the progressive deterioration of teeth, restore optimal esthetics and function, and enable staged full-mouth reconstructive treatment in a way that minimizes upfront costs and maximizes dental insurance reimbursements.

As 3D printing materials continue to evolve, it is likely that the profession will see further advancements in related techniques that enhance the efficacy and accessibility of these innovative restorative solutions. Ultimately, by harnessing the power of 3D printing, dentists can provide their patients with a higher standard of care that prioritizes conservation, affordability, and long-term oral health.

Andrew C. Johnson, DDS, MDS, CDT
Fellow
American College of Prosthodontists
Omnismile Digital Dental Solutions
Fayetteville, Arkansas